/**********************************************************************
 *
 * StackWalker.cpp
 * https://github.com/JochenKalmbach/StackWalker
 *
 * Old location: http://stackwalker.codeplex.com/
 *
 *
 * History:
 *  2005-07-27   v1    - First public release on http://www.codeproject.com/
 *                       http://www.codeproject.com/threads/StackWalker.asp
 *  2005-07-28   v2    - Changed the params of the constructor and ShowCallstack
 *                       (to simplify the usage)
 *  2005-08-01   v3    - Changed to use 'CONTEXT_FULL' instead of CONTEXT_ALL
 *                       (should also be enough)
 *                     - Changed to compile correctly with the PSDK of VC7.0
 *                       (GetFileVersionInfoSizeA and GetFileVersionInfoA is wrongly defined:
 *                        it uses LPSTR instead of LPCSTR as first parameter)
 *                     - Added declarations to support VC5/6 without using 'dbghelp.h'
 *                     - Added a 'pUserData' member to the ShowCallstack function and the
 *                       PReadProcessMemoryRoutine declaration (to pass some user-defined data,
 *                       which can be used in the readMemoryFunction-callback)
 *  2005-08-02   v4    - OnSymInit now also outputs the OS-Version by default
 *                     - Added example for doing an exception-callstack-walking in main.cpp
 *                       (thanks to owillebo: http://www.codeproject.com/script/profile/whos_who.asp?id=536268)
 *  2005-08-05   v5    - Removed most Lint (http://www.gimpel.com/) errors... thanks to Okko Willeboordse!
 *  2008-08-04   v6    - Fixed Bug: Missing LEAK-end-tag
 *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=2502890#xx2502890xx
 *                       Fixed Bug: Compiled with "WIN32_LEAN_AND_MEAN"
 *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=1824718#xx1824718xx
 *                       Fixed Bug: Compiling with "/Wall"
 *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=2638243#xx2638243xx
 *                       Fixed Bug: Now checking SymUseSymSrv
 *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1388979#xx1388979xx
 *                       Fixed Bug: Support for recursive function calls
 *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1434538#xx1434538xx
 *                       Fixed Bug: Missing FreeLibrary call in "GetModuleListTH32"
 *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=1326923#xx1326923xx
 *                       Fixed Bug: SymDia is number 7, not 9!
 *  2008-09-11   v7      For some (undocumented) reason, dbhelp.h is needing a packing of 8!
 *                       Thanks to Teajay which reported the bug...
 *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=2718933#xx2718933xx
 *  2008-11-27   v8      Debugging Tools for Windows are now stored in a different directory
 *                       Thanks to Luiz Salamon which reported this "bug"...
 *                       http://www.codeproject.com/KB/threads/StackWalker.aspx?msg=2822736#xx2822736xx
 *  2009-04-10   v9      License slightly corrected (<ORGANIZATION> replaced)
 *  2009-11-01   v10     Moved to http://stackwalker.codeplex.com/
 *  2009-11-02   v11     Now try to use IMAGEHLP_MODULE64_V3 if available
 *  2010-04-15   v12     Added support for VS2010 RTM
 *  2010-05-25   v13     Now using secure MyStrcCpy. Thanks to luke.simon:
 *                       http://www.codeproject.com/KB/applications/leakfinder.aspx?msg=3477467#xx3477467xx
 *  2013-01-07   v14     Runtime Check Error VS2010 Debug Builds fixed:
 *                       http://stackwalker.codeplex.com/workitem/10511
 *
 *
 * LICENSE (http://www.opensource.org/licenses/bsd-license.php)
 *
 *   Copyright (c) 2005-2013, Jochen Kalmbach
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without modification,
 *   are permitted provided that the following conditions are met:
 *
 *   Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *   Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *   Neither the name of Jochen Kalmbach nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 *   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 *   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 **********************************************************************/

#if defined(_M_IA64) || defined(_M_X64) || defined(_M_IX86)

#include "StackWalker.h"

#include <stdio.h>
#include <stdlib.h>
#include <tchar.h>
#include <windows.h>
#include <new>

#pragma comment(lib, "version.lib") // for "VerQueryValue"

#pragma warning(disable : 4826)
#if _MSC_VER >= 1900
#pragma warning(disable : 4091)   // For fix unnamed enums from DbgHelp.h
#endif


 // If VC7 and later, then use the shipped 'dbghelp.h'-file
#pragma pack(push, 8)
#if _MSC_VER >= 1300
#include <dbghelp.h>
#else
// inline the important dbghelp.h-declarations...
typedef enum
{
    SymNone = 0,
    SymCoff,
    SymCv,
    SymPdb,
    SymExport,
    SymDeferred,
    SymSym,
    SymDia,
    SymVirtual,
    NumSymTypes
} SYM_TYPE;
typedef struct _IMAGEHLP_LINE64
{
    DWORD   SizeOfStruct; // set to sizeof(IMAGEHLP_LINE64)
    PVOID   Key;          // internal
    DWORD   LineNumber;   // line number in file
    PCHAR   FileName;     // full filename
    DWORD64 Address;      // first instruction of line
} IMAGEHLP_LINE64, * PIMAGEHLP_LINE64;
typedef struct _IMAGEHLP_MODULE64
{
    DWORD    SizeOfStruct;         // set to sizeof(IMAGEHLP_MODULE64)
    DWORD64  BaseOfImage;          // base load address of module
    DWORD    ImageSize;            // virtual size of the loaded module
    DWORD    TimeDateStamp;        // date/time stamp from pe header
    DWORD    CheckSum;             // checksum from the pe header
    DWORD    NumSyms;              // number of symbols in the symbol table
    SYM_TYPE SymType;              // type of symbols loaded
    CHAR     ModuleName[32];       // module name
    CHAR     ImageName[256];       // image name
    CHAR     LoadedImageName[256]; // symbol file name
} IMAGEHLP_MODULE64, * PIMAGEHLP_MODULE64;
typedef struct _IMAGEHLP_SYMBOL64
{
    DWORD   SizeOfStruct;  // set to sizeof(IMAGEHLP_SYMBOL64)
    DWORD64 Address;       // virtual address including dll base address
    DWORD   Size;          // estimated size of symbol, can be zero
    DWORD   Flags;         // info about the symbols, see the SYMF defines
    DWORD   MaxNameLength; // maximum size of symbol name in 'Name'
    CHAR    Name[1];       // symbol name (null terminated string)
} IMAGEHLP_SYMBOL64, * PIMAGEHLP_SYMBOL64;
typedef enum
{
    AddrMode1616,
    AddrMode1632,
    AddrModeReal,
    AddrModeFlat
} ADDRESS_MODE;
typedef struct _tagADDRESS64
{
    DWORD64      Offset;
    WORD         Segment;
    ADDRESS_MODE Mode;
} ADDRESS64, * LPADDRESS64;
typedef struct _KDHELP64
{
    DWORD64 Thread;
    DWORD   ThCallbackStack;
    DWORD   ThCallbackBStore;
    DWORD   NextCallback;
    DWORD   FramePointer;
    DWORD64 KiCallUserMode;
    DWORD64 KeUserCallbackDispatcher;
    DWORD64 SystemRangeStart;
    DWORD64 Reserved[8];
} KDHELP64, * PKDHELP64;
typedef struct _tagSTACKFRAME64
{
    ADDRESS64 AddrPC;         // program counter
    ADDRESS64 AddrReturn;     // return address
    ADDRESS64 AddrFrame;      // frame pointer
    ADDRESS64 AddrStack;      // stack pointer
    ADDRESS64 AddrBStore;     // backing store pointer
    PVOID     FuncTableEntry; // pointer to pdata/fpo or NULL
    DWORD64   Params[4];      // possible arguments to the function
    BOOL      Far;            // WOW far call
    BOOL      Virtual;        // is this a virtual frame?
    DWORD64   Reserved[3];
    KDHELP64  KdHelp;
} STACKFRAME64, * LPSTACKFRAME64;
typedef BOOL(__stdcall* PREAD_PROCESS_MEMORY_ROUTINE64)(HANDLE  hProcess,
    DWORD64 qwBaseAddress,
    PVOID   lpBuffer,
    DWORD   nSize,
    LPDWORD lpNumberOfBytesRead);
typedef PVOID(__stdcall* PFUNCTION_TABLE_ACCESS_ROUTINE64)(HANDLE hProcess, DWORD64 AddrBase);
typedef DWORD64(__stdcall* PGET_MODULE_BASE_ROUTINE64)(HANDLE hProcess, DWORD64 Address);
typedef DWORD64(__stdcall* PTRANSLATE_ADDRESS_ROUTINE64)(HANDLE      hProcess,
    HANDLE      hThread,
    LPADDRESS64 lpaddr);

// clang-format off
#define SYMOPT_CASE_INSENSITIVE         0x00000001
#define SYMOPT_UNDNAME                  0x00000002
#define SYMOPT_DEFERRED_LOADS           0x00000004
#define SYMOPT_NO_CPP                   0x00000008
#define SYMOPT_LOAD_LINES               0x00000010
#define SYMOPT_OMAP_FIND_NEAREST        0x00000020
#define SYMOPT_LOAD_ANYTHING            0x00000040
#define SYMOPT_IGNORE_CVREC             0x00000080
#define SYMOPT_NO_UNQUALIFIED_LOADS     0x00000100
#define SYMOPT_FAIL_CRITICAL_ERRORS     0x00000200
#define SYMOPT_EXACT_SYMBOLS            0x00000400
#define SYMOPT_ALLOW_ABSOLUTE_SYMBOLS   0x00000800
#define SYMOPT_IGNORE_NT_SYMPATH        0x00001000
#define SYMOPT_INCLUDE_32BIT_MODULES    0x00002000
#define SYMOPT_PUBLICS_ONLY             0x00004000
#define SYMOPT_NO_PUBLICS               0x00008000
#define SYMOPT_AUTO_PUBLICS             0x00010000
#define SYMOPT_NO_IMAGE_SEARCH          0x00020000
#define SYMOPT_SECURE                   0x00040000
#define SYMOPT_DEBUG                    0x80000000
#define UNDNAME_COMPLETE                 (0x0000) // Enable full undecoration
#define UNDNAME_NAME_ONLY                (0x1000) // Crack only the name for primary declaration;
// clang-format on

#endif // _MSC_VER < 1300
#pragma pack(pop)

// Some missing defines (for VC5/6):
#ifndef INVALID_FILE_ATTRIBUTES
#define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
#endif

// secure-CRT_functions are only available starting with VC8
#if _MSC_VER < 1400
#define strcpy_s(dst, len, src) strcpy(dst, src)
#define strncpy_s(dst, len, src, maxLen) strncpy(dst, len, src)
#define strcat_s(dst, len, src) strcat(dst, src)
#define _snprintf_s _snprintf
#define _tcscat_s _tcscat
#endif

static void MyStrCpy(char* szDest, size_t nMaxDestSize, const char* szSrc)
{
    if (nMaxDestSize <= 0)
        return;
    strncpy_s(szDest, nMaxDestSize, szSrc, _TRUNCATE);
    // INFO: _TRUNCATE will ensure that it is null-terminated;
    // but with older compilers (<1400) it uses "strncpy" and this does not!)
    szDest[nMaxDestSize - 1] = 0;
} // MyStrCpy

// Normally it should be enough to use 'CONTEXT_FULL' (better would be 'CONTEXT_ALL')
#define USED_CONTEXT_FLAGS CONTEXT_FULL

class StackWalkerInternal
{
public:
    StackWalkerInternal(StackWalker* parent, HANDLE hProcess, PCONTEXT ctx)
    {
        m_parent = parent;
        m_hDbhHelp = NULL;
        pSC = NULL;
        m_hProcess = hProcess;
        pSFTA = NULL;
        pSGLFA = NULL;
        pSGMB = NULL;
        pSGMI = NULL;
        pSGO = NULL;
        pSGSFA = NULL;
        pSI = NULL;
        pSLM = NULL;
        pSSO = NULL;
        pSW = NULL;
        pUDSN = NULL;
        pSGSP = NULL;
        m_ctx.ContextFlags = 0;
        if (ctx != NULL)
            m_ctx = *ctx;
    }

    ~StackWalkerInternal()
    {
        if (pSC != NULL)
            pSC(m_hProcess); // SymCleanup
        if (m_hDbhHelp != NULL)
            FreeLibrary(m_hDbhHelp);
        m_hDbhHelp = NULL;
        m_parent = NULL;
    }

    BOOL Init(LPCSTR szSymPath)
    {
        if (m_parent == NULL)
            return FALSE;
        // Dynamically load the Entry-Points for dbghelp.dll:
        // First try to load the newest one from
        TCHAR szTemp[4096];
        // But before we do this, we first check if the ".local" file exists
        if (GetModuleFileName(NULL, szTemp, 4096) > 0)
        {
            _tcscat_s(szTemp, _T(".local"));
            if (GetFileAttributes(szTemp) == INVALID_FILE_ATTRIBUTES)
            {
                // ".local" file does not exist, so we can try to load the dbghelp.dll from the "Debugging Tools for Windows"
                // Ok, first try the new path according to the architecture:
#ifdef _M_IX86
                if ((m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0))
                {
                    _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (x86)\\dbghelp.dll"));
                    // now check if the file exists:
                    if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
                    {
                        m_hDbhHelp = LoadLibrary(szTemp);
                    }
                }
#elif _M_X64
                if ((m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0))
                {
                    _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (x64)\\dbghelp.dll"));
                    // now check if the file exists:
                    if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
                    {
                        m_hDbhHelp = LoadLibrary(szTemp);
                    }
                }
#elif _M_IA64
                if ((m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0))
                {
                    _tcscat_s(szTemp, _T("\\Debugging Tools for Windows (ia64)\\dbghelp.dll"));
                    // now check if the file exists:
                    if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
                    {
                        m_hDbhHelp = LoadLibrary(szTemp);
                    }
                }
#endif
                // If still not found, try the old directories...
                if ((m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0))
                {
                    _tcscat_s(szTemp, _T("\\Debugging Tools for Windows\\dbghelp.dll"));
                    // now check if the file exists:
                    if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
                    {
                        m_hDbhHelp = LoadLibrary(szTemp);
                    }
                }
#if defined _M_X64 || defined _M_IA64
                // Still not found? Then try to load the (old) 64-Bit version:
                if ((m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0))
                {
                    _tcscat_s(szTemp, _T("\\Debugging Tools for Windows 64-Bit\\dbghelp.dll"));
                    if (GetFileAttributes(szTemp) != INVALID_FILE_ATTRIBUTES)
                    {
                        m_hDbhHelp = LoadLibrary(szTemp);
                    }
                }
#endif
            }
        }
        if (m_hDbhHelp == NULL) // if not already loaded, try to load a default-one
            m_hDbhHelp = LoadLibrary(_T("dbghelp.dll"));
        if (m_hDbhHelp == NULL)
            return FALSE;
        pSI = (tSI)GetProcAddress(m_hDbhHelp, "SymInitialize");
        pSC = (tSC)GetProcAddress(m_hDbhHelp, "SymCleanup");

        pSW = (tSW)GetProcAddress(m_hDbhHelp, "StackWalk64");
        pSGO = (tSGO)GetProcAddress(m_hDbhHelp, "SymGetOptions");
        pSSO = (tSSO)GetProcAddress(m_hDbhHelp, "SymSetOptions");

        pSFTA = (tSFTA)GetProcAddress(m_hDbhHelp, "SymFunctionTableAccess64");
        pSGLFA = (tSGLFA)GetProcAddress(m_hDbhHelp, "SymGetLineFromAddr64");
        pSGMB = (tSGMB)GetProcAddress(m_hDbhHelp, "SymGetModuleBase64");
        pSGMI = (tSGMI)GetProcAddress(m_hDbhHelp, "SymGetModuleInfo64");
        pSGSFA = (tSGSFA)GetProcAddress(m_hDbhHelp, "SymGetSymFromAddr64");
        pUDSN = (tUDSN)GetProcAddress(m_hDbhHelp, "UnDecorateSymbolName");
        pSLM = (tSLM)GetProcAddress(m_hDbhHelp, "SymLoadModule64");
        pSGSP = (tSGSP)GetProcAddress(m_hDbhHelp, "SymGetSearchPath");

        if (pSC == NULL || pSFTA == NULL || pSGMB == NULL || pSGMI == NULL || pSGO == NULL ||
            pSGSFA == NULL || pSI == NULL || pSSO == NULL || pSW == NULL || pUDSN == NULL ||
            pSLM == NULL)
        {
            FreeLibrary(m_hDbhHelp);
            m_hDbhHelp = NULL;
            pSC = NULL;
            return FALSE;
        }

        // SymInitialize
        if (this->pSI(m_hProcess, szSymPath, FALSE) == FALSE)
            this->m_parent->OnDbgHelpErr("SymInitialize", GetLastError(), 0);

        DWORD symOptions = this->pSGO(); // SymGetOptions
        symOptions |= SYMOPT_LOAD_LINES;
        symOptions |= SYMOPT_FAIL_CRITICAL_ERRORS;
        //symOptions |= SYMOPT_NO_PROMPTS;
        // SymSetOptions
        symOptions = this->pSSO(symOptions);

        char buf[StackWalker::STACKWALK_MAX_NAMELEN] = { 0 };
        if (this->pSGSP != NULL)
        {
            if (this->pSGSP(m_hProcess, buf, StackWalker::STACKWALK_MAX_NAMELEN) == FALSE)
                this->m_parent->OnDbgHelpErr("SymGetSearchPath", GetLastError(), 0);
        }
        char  szUserName[1024] = { 0 };
        DWORD dwSize = 1024;
        GetUserNameA(szUserName, &dwSize);
        this->m_parent->OnSymInit(buf, symOptions, szUserName);

        return TRUE;
    }

    StackWalker* m_parent;

    CONTEXT m_ctx;
    HMODULE m_hDbhHelp;
    HANDLE  m_hProcess;

#pragma pack(push, 8)
    typedef struct _IMAGEHLP_MODULE64_V3
    {
        DWORD    SizeOfStruct;         // set to sizeof(IMAGEHLP_MODULE64)
        DWORD64  BaseOfImage;          // base load address of module
        DWORD    ImageSize;            // virtual size of the loaded module
        DWORD    TimeDateStamp;        // date/time stamp from pe header
        DWORD    CheckSum;             // checksum from the pe header
        DWORD    NumSyms;              // number of symbols in the symbol table
        SYM_TYPE SymType;              // type of symbols loaded
        CHAR     ModuleName[32];       // module name
        CHAR     ImageName[256];       // image name
        CHAR     LoadedImageName[256]; // symbol file name
        // new elements: 07-Jun-2002
        CHAR  LoadedPdbName[256];   // pdb file name
        DWORD CVSig;                // Signature of the CV record in the debug directories
        CHAR  CVData[MAX_PATH * 3]; // Contents of the CV record
        DWORD PdbSig;               // Signature of PDB
        GUID  PdbSig70;             // Signature of PDB (VC 7 and up)
        DWORD PdbAge;               // DBI age of pdb
        BOOL  PdbUnmatched;         // loaded an unmatched pdb
        BOOL  DbgUnmatched;         // loaded an unmatched dbg
        BOOL  LineNumbers;          // we have line number information
        BOOL  GlobalSymbols;        // we have internal symbol information
        BOOL  TypeInfo;             // we have type information
        // new elements: 17-Dec-2003
        BOOL SourceIndexed; // pdb supports source server
        BOOL Publics;       // contains public symbols
    } IMAGEHLP_MODULE64_V3, * PIMAGEHLP_MODULE64_V3;

    typedef struct _IMAGEHLP_MODULE64_V2
    {
        DWORD    SizeOfStruct;         // set to sizeof(IMAGEHLP_MODULE64)
        DWORD64  BaseOfImage;          // base load address of module
        DWORD    ImageSize;            // virtual size of the loaded module
        DWORD    TimeDateStamp;        // date/time stamp from pe header
        DWORD    CheckSum;             // checksum from the pe header
        DWORD    NumSyms;              // number of symbols in the symbol table
        SYM_TYPE SymType;              // type of symbols loaded
        CHAR     ModuleName[32];       // module name
        CHAR     ImageName[256];       // image name
        CHAR     LoadedImageName[256]; // symbol file name
    } IMAGEHLP_MODULE64_V2, * PIMAGEHLP_MODULE64_V2;
#pragma pack(pop)

    // SymCleanup()
    typedef BOOL(__stdcall* tSC)(IN HANDLE hProcess);
    tSC pSC;

    // SymFunctionTableAccess64()
    typedef PVOID(__stdcall* tSFTA)(HANDLE hProcess, DWORD64 AddrBase);
    tSFTA pSFTA;

    // SymGetLineFromAddr64()
    typedef BOOL(__stdcall* tSGLFA)(IN HANDLE hProcess,
        IN DWORD64 dwAddr,
        OUT PDWORD pdwDisplacement,
        OUT PIMAGEHLP_LINE64 Line);
    tSGLFA pSGLFA;

    // SymGetModuleBase64()
    typedef DWORD64(__stdcall* tSGMB)(IN HANDLE hProcess, IN DWORD64 dwAddr);
    tSGMB pSGMB;

    // SymGetModuleInfo64()
    typedef BOOL(__stdcall* tSGMI)(IN HANDLE hProcess,
        IN DWORD64 dwAddr,
        OUT IMAGEHLP_MODULE64_V3* ModuleInfo);
    tSGMI pSGMI;

    // SymGetOptions()
    typedef DWORD(__stdcall* tSGO)(VOID);
    tSGO pSGO;

    // SymGetSymFromAddr64()
    typedef BOOL(__stdcall* tSGSFA)(IN HANDLE hProcess,
        IN DWORD64 dwAddr,
        OUT PDWORD64 pdwDisplacement,
        OUT PIMAGEHLP_SYMBOL64 Symbol);
    tSGSFA pSGSFA;

    // SymInitialize()
    typedef BOOL(__stdcall* tSI)(IN HANDLE hProcess, IN LPCSTR UserSearchPath, IN BOOL fInvadeProcess);
    tSI pSI;

    // SymLoadModule64()
    typedef DWORD64(__stdcall* tSLM)(IN HANDLE hProcess,
        IN HANDLE hFile,
        IN LPCSTR ImageName,
        IN LPCSTR ModuleName,
        IN DWORD64 BaseOfDll,
        IN DWORD SizeOfDll);
    tSLM pSLM;

    // SymSetOptions()
    typedef DWORD(__stdcall* tSSO)(IN DWORD SymOptions);
    tSSO pSSO;

    // StackWalk64()
    typedef BOOL(__stdcall* tSW)(DWORD                            MachineType,
        HANDLE                           hProcess,
        HANDLE                           hThread,
        LPSTACKFRAME64                   StackFrame,
        PVOID                            ContextRecord,
        PREAD_PROCESS_MEMORY_ROUTINE64   ReadMemoryRoutine,
        PFUNCTION_TABLE_ACCESS_ROUTINE64 FunctionTableAccessRoutine,
        PGET_MODULE_BASE_ROUTINE64       GetModuleBaseRoutine,
        PTRANSLATE_ADDRESS_ROUTINE64     TranslateAddress);
    tSW pSW;

    // UnDecorateSymbolName()
    typedef DWORD(__stdcall WINAPI* tUDSN)(PCSTR DecoratedName,
        PSTR  UnDecoratedName,
        DWORD UndecoratedLength,
        DWORD Flags);
    tUDSN pUDSN;

    typedef BOOL(__stdcall WINAPI* tSGSP)(HANDLE hProcess, PSTR SearchPath, DWORD SearchPathLength);
    tSGSP pSGSP;

private:
    // **************************************** ToolHelp32 ************************
#define MAX_MODULE_NAME32 255
#define TH32CS_SNAPMODULE 0x00000008
#pragma pack(push, 8)
    typedef struct tagMODULEENTRY32
    {
        DWORD   dwSize;
        DWORD   th32ModuleID;  // This module
        DWORD   th32ProcessID; // owning process
        DWORD   GlblcntUsage;  // Global usage count on the module
        DWORD   ProccntUsage;  // Module usage count in th32ProcessID's context
        BYTE* modBaseAddr;   // Base address of module in th32ProcessID's context
        DWORD   modBaseSize;   // Size in bytes of module starting at modBaseAddr
        HMODULE hModule;       // The hModule of this module in th32ProcessID's context
        char    szModule[MAX_MODULE_NAME32 + 1];
        char    szExePath[MAX_PATH];
    } MODULEENTRY32;
    typedef MODULEENTRY32* PMODULEENTRY32;
    typedef MODULEENTRY32* LPMODULEENTRY32;
#pragma pack(pop)

    BOOL GetModuleListTH32(HANDLE hProcess, DWORD pid)
    {
        // CreateToolhelp32Snapshot()
        typedef HANDLE(__stdcall* tCT32S)(DWORD dwFlags, DWORD th32ProcessID);
        // Module32First()
        typedef BOOL(__stdcall* tM32F)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);
        // Module32Next()
        typedef BOOL(__stdcall* tM32N)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);

        // try both dlls...
        const TCHAR* dllname[] = { _T("kernel32.dll"), _T("tlhelp32.dll") };
        HINSTANCE    hToolhelp = NULL;
        tCT32S       pCT32S = NULL;
        tM32F        pM32F = NULL;
        tM32N        pM32N = NULL;

        HANDLE        hSnap;
        MODULEENTRY32 me;
        me.dwSize = sizeof(me);
        BOOL   keepGoing;
        size_t i;

        for (i = 0; i < (sizeof(dllname) / sizeof(dllname[0])); i++)
        {
            hToolhelp = LoadLibrary(dllname[i]);
            if (hToolhelp == NULL)
                continue;
            pCT32S = (tCT32S)GetProcAddress(hToolhelp, "CreateToolhelp32Snapshot");
            pM32F = (tM32F)GetProcAddress(hToolhelp, "Module32First");
            pM32N = (tM32N)GetProcAddress(hToolhelp, "Module32Next");
            if ((pCT32S != NULL) && (pM32F != NULL) && (pM32N != NULL))
                break; // found the functions!
            FreeLibrary(hToolhelp);
            hToolhelp = NULL;
        }

        if (hToolhelp == NULL)
            return FALSE;

        hSnap = pCT32S(TH32CS_SNAPMODULE, pid);
        if (hSnap == (HANDLE)-1)
        {
            FreeLibrary(hToolhelp);
            return FALSE;
        }

        keepGoing = !!pM32F(hSnap, &me);
        int cnt = 0;
        while (keepGoing)
        {
            this->LoadModule(hProcess, me.szExePath, me.szModule, (DWORD64)me.modBaseAddr,
                me.modBaseSize);
            cnt++;
            keepGoing = !!pM32N(hSnap, &me);
        }
        CloseHandle(hSnap);
        FreeLibrary(hToolhelp);
        if (cnt <= 0)
            return FALSE;
        return TRUE;
    } // GetModuleListTH32

    // **************************************** PSAPI ************************
    typedef struct _MODULEINFO
    {
        LPVOID lpBaseOfDll;
        DWORD  SizeOfImage;
        LPVOID EntryPoint;
    } MODULEINFO, * LPMODULEINFO;

    BOOL GetModuleListPSAPI(HANDLE hProcess)
    {
        // EnumProcessModules()
        typedef BOOL(__stdcall* tEPM)(HANDLE hProcess, HMODULE* lphModule, DWORD cb,
            LPDWORD lpcbNeeded);
        // GetModuleFileNameEx()
        typedef DWORD(__stdcall* tGMFNE)(HANDLE hProcess, HMODULE hModule, LPSTR lpFilename,
            DWORD nSize);
        // GetModuleBaseName()
        typedef DWORD(__stdcall* tGMBN)(HANDLE hProcess, HMODULE hModule, LPSTR lpFilename,
            DWORD nSize);
        // GetModuleInformation()
        typedef BOOL(__stdcall* tGMI)(HANDLE hProcess, HMODULE hModule, LPMODULEINFO pmi, DWORD nSize);

        HINSTANCE hPsapi;
        tEPM      pEPM;
        tGMFNE    pGMFNE;
        tGMBN     pGMBN;
        tGMI      pGMI;

        DWORD i;
        //ModuleEntry e;
        DWORD        cbNeeded;
        MODULEINFO   mi;
        HMODULE* hMods = NULL;
        char* tt = NULL;
        char* tt2 = NULL;
        const SIZE_T TTBUFLEN = 8096;
        int          cnt = 0;

        hPsapi = LoadLibrary(_T("psapi.dll"));
        if (hPsapi == NULL)
            return FALSE;

        pEPM = (tEPM)GetProcAddress(hPsapi, "EnumProcessModules");
        pGMFNE = (tGMFNE)GetProcAddress(hPsapi, "GetModuleFileNameExA");
        pGMBN = (tGMFNE)GetProcAddress(hPsapi, "GetModuleBaseNameA");
        pGMI = (tGMI)GetProcAddress(hPsapi, "GetModuleInformation");
        if ((pEPM == NULL) || (pGMFNE == NULL) || (pGMBN == NULL) || (pGMI == NULL))
        {
            // we couldn't find all functions
            FreeLibrary(hPsapi);
            return FALSE;
        }

        hMods = (HMODULE*)malloc(sizeof(HMODULE) * (TTBUFLEN / sizeof(HMODULE)));
        tt = (char*)malloc(sizeof(char) * TTBUFLEN);
        tt2 = (char*)malloc(sizeof(char) * TTBUFLEN);
        if ((hMods == NULL) || (tt == NULL) || (tt2 == NULL))
            goto cleanup;

        if (!pEPM(hProcess, hMods, TTBUFLEN, &cbNeeded))
        {
            //_ftprintf(fLogFile, _T("%lu: EPM failed, GetLastError = %lu\n"), g_dwShowCount, gle );
            goto cleanup;
        }

        if (cbNeeded > TTBUFLEN)
        {
            //_ftprintf(fLogFile, _T("%lu: More than %lu module handles. Huh?\n"), g_dwShowCount, lenof( hMods ) );
            goto cleanup;
        }

        for (i = 0; i < cbNeeded / sizeof(hMods[0]); i++)
        {
            // base address, size
            pGMI(hProcess, hMods[i], &mi, sizeof(mi));
            // image file name
            tt[0] = 0;
            pGMFNE(hProcess, hMods[i], tt, TTBUFLEN);
            // module name
            tt2[0] = 0;
            pGMBN(hProcess, hMods[i], tt2, TTBUFLEN);

            DWORD dwRes = this->LoadModule(hProcess, tt, tt2, (DWORD64)mi.lpBaseOfDll, mi.SizeOfImage);
            if (dwRes != ERROR_SUCCESS)
                this->m_parent->OnDbgHelpErr("LoadModule", dwRes, 0);
            cnt++;
        }

    cleanup:
        if (hPsapi != NULL)
            FreeLibrary(hPsapi);
        if (tt2 != NULL)
            free(tt2);
        if (tt != NULL)
            free(tt);
        if (hMods != NULL)
            free(hMods);

        return cnt != 0;
    } // GetModuleListPSAPI

    DWORD LoadModule(HANDLE hProcess, LPCSTR img, LPCSTR mod, DWORD64 baseAddr, DWORD size)
    {
        CHAR* szImg = _strdup(img);
        CHAR* szMod = _strdup(mod);
        DWORD result = ERROR_SUCCESS;
        if ((szImg == NULL) || (szMod == NULL))
            result = ERROR_NOT_ENOUGH_MEMORY;
        else
        {
            if (pSLM(hProcess, 0, szImg, szMod, baseAddr, size) == 0)
                result = GetLastError();
        }
        ULONGLONG fileVersion = 0;
        if ((m_parent != NULL) && (szImg != NULL))
        {
            // try to retrieve the file-version:
            if ((this->m_parent->m_options & StackWalker::RetrieveFileVersion) != 0)
            {
                VS_FIXEDFILEINFO* fInfo = NULL;
                DWORD             dwHandle;
                DWORD             dwSize = GetFileVersionInfoSizeA(szImg, &dwHandle);
                if (dwSize > 0)
                {
                    LPVOID vData = malloc(dwSize);
                    if (vData != NULL)
                    {
                        if (GetFileVersionInfoA(szImg, dwHandle, dwSize, vData) != 0)
                        {
                            UINT  len;
                            TCHAR szSubBlock[] = _T("\\");
                            if (VerQueryValue(vData, szSubBlock, (LPVOID*)&fInfo, &len) == 0)
                                fInfo = NULL;
                            else
                            {
                                fileVersion =
                                    ((ULONGLONG)fInfo->dwFileVersionLS) + ((ULONGLONG)fInfo->dwFileVersionMS << 32);
                            }
                        }
                        free(vData);
                    }
                }
            }

            // Retrieve some additional-infos about the module
            IMAGEHLP_MODULE64_V3 Module;
            const char* szSymType = "-unknown-";
            if (this->GetModuleInfo(hProcess, baseAddr, &Module) != FALSE)
            {
                switch (Module.SymType)
                {
                case SymNone:
                    szSymType = "-nosymbols-";
                    break;
                case SymCoff: // 1
                    szSymType = "COFF";
                    break;
                case SymCv: // 2
                    szSymType = "CV";
                    break;
                case SymPdb: // 3
                    szSymType = "PDB";
                    break;
                case SymExport: // 4
                    szSymType = "-exported-";
                    break;
                case SymDeferred: // 5
                    szSymType = "-deferred-";
                    break;
                case SymSym: // 6
                    szSymType = "SYM";
                    break;
                case 7: // SymDia:
                    szSymType = "DIA";
                    break;
                case 8: //SymVirtual:
                    szSymType = "Virtual";
                    break;
                }
            }
            LPCSTR pdbName = Module.LoadedImageName;
            if (Module.LoadedPdbName[0] != 0)
                pdbName = Module.LoadedPdbName;
            this->m_parent->OnLoadModule(img, mod, baseAddr, size, result, szSymType, pdbName,
                fileVersion);
        }
        if (szImg != NULL)
            free(szImg);
        if (szMod != NULL)
            free(szMod);
        return result;
    }

public:
    BOOL LoadModules(HANDLE hProcess, DWORD dwProcessId)
    {
        // first try toolhelp32
        if (GetModuleListTH32(hProcess, dwProcessId))
            return true;
        // then try psapi
        return GetModuleListPSAPI(hProcess);
    }

    BOOL GetModuleInfo(HANDLE hProcess, DWORD64 baseAddr, IMAGEHLP_MODULE64_V3* pModuleInfo)
    {
        memset(pModuleInfo, 0, sizeof(IMAGEHLP_MODULE64_V3));
        if (this->pSGMI == NULL)
        {
            SetLastError(ERROR_DLL_INIT_FAILED);
            return FALSE;
        }
        // First try to use the larger ModuleInfo-Structure
        pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V3);
        void* pData = malloc(
            4096); // reserve enough memory, so the bug in v6.3.5.1 does not lead to memory-overwrites...
        if (pData == NULL)
        {
            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
            return FALSE;
        }
        memcpy(pData, pModuleInfo, sizeof(IMAGEHLP_MODULE64_V3));
        static bool s_useV3Version = true;
        if (s_useV3Version)
        {
            if (this->pSGMI(hProcess, baseAddr, (IMAGEHLP_MODULE64_V3*)pData) != FALSE)
            {
                // only copy as much memory as is reserved...
                memcpy(pModuleInfo, pData, sizeof(IMAGEHLP_MODULE64_V3));
                pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V3);
                free(pData);
                return TRUE;
            }
            s_useV3Version = false; // to prevent unnecessary calls with the larger struct...
        }

        // could not retrieve the bigger structure, try with the smaller one (as defined in VC7.1)...
        pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V2);
        memcpy(pData, pModuleInfo, sizeof(IMAGEHLP_MODULE64_V2));
        if (this->pSGMI(hProcess, baseAddr, (IMAGEHLP_MODULE64_V3*)pData) != FALSE)
        {
            // only copy as much memory as is reserved...
            memcpy(pModuleInfo, pData, sizeof(IMAGEHLP_MODULE64_V2));
            pModuleInfo->SizeOfStruct = sizeof(IMAGEHLP_MODULE64_V2);
            free(pData);
            return TRUE;
        }
        free(pData);
        SetLastError(ERROR_DLL_INIT_FAILED);
        return FALSE;
    }
};

// #############################################################

#if defined(_MSC_VER) && _MSC_VER >= 1400 && _MSC_VER < 1900
extern "C" void* __cdecl _getptd();
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1900
extern "C" void** __cdecl __current_exception_context();
#endif

static PCONTEXT get_current_exception_context()
{
    PCONTEXT* pctx = NULL;
#if defined(_MSC_VER) && _MSC_VER >= 1400 && _MSC_VER < 1900  
    LPSTR ptd = (LPSTR)_getptd();
    if (ptd)
        pctx = (PCONTEXT*)(ptd + (sizeof(void*) == 4 ? 0x8C : 0xF8));
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1900
    pctx = (PCONTEXT*)__current_exception_context();
#endif
    return pctx ? *pctx : NULL;
}

bool StackWalker::Init(ExceptType extype, int options, LPCSTR szSymPath, DWORD dwProcessId,
    HANDLE hProcess, PEXCEPTION_POINTERS exp)
{
    PCONTEXT ctx = NULL;
    if (extype == AfterCatch)
        ctx = get_current_exception_context();
    if (extype == AfterExcept && exp)
        ctx = exp->ContextRecord;
    this->m_options = options;
    this->m_modulesLoaded = FALSE;
    this->m_szSymPath = NULL;
    this->m_MaxRecursionCount = 1000;
    this->m_sw = NULL;
    SetTargetProcess(dwProcessId, hProcess);
    SetSymPath(szSymPath);
    /* MSVC ignore std::nothrow specifier for `new` operator */
    LPVOID buf = malloc(sizeof(StackWalkerInternal));
    if (!buf)
        return false;
    memset(buf, 0, sizeof(StackWalkerInternal));
    this->m_sw = new(buf) StackWalkerInternal(this, this->m_hProcess, ctx);  // placement new
    return true;
}

StackWalker::StackWalker(DWORD dwProcessId, HANDLE hProcess)
{
    Init(NonExcept, OptionsAll, NULL, dwProcessId, hProcess);
}

StackWalker::StackWalker(int options, LPCSTR szSymPath, DWORD dwProcessId, HANDLE hProcess)
{
    Init(NonExcept, options, szSymPath, dwProcessId, hProcess);
}

StackWalker::StackWalker(ExceptType extype, int options, PEXCEPTION_POINTERS exp)
{
    Init(extype, options, NULL, GetCurrentProcessId(), GetCurrentProcess(), exp);
}

StackWalker::~StackWalker()
{
    SetSymPath(NULL);
    if (m_sw != NULL) {
        m_sw->~StackWalkerInternal();  // call the object's destructor
        free(m_sw);
    }
    m_sw = NULL;
}

bool StackWalker::SetSymPath(LPCSTR szSymPath)
{
    if (m_szSymPath)
        free(m_szSymPath);
    m_szSymPath = NULL;
    if (szSymPath == NULL)
        return true;
    m_szSymPath = _strdup(szSymPath);
    if (m_szSymPath)
        m_options |= SymBuildPath;
    return true;
}

bool StackWalker::SetTargetProcess(DWORD dwProcessId, HANDLE hProcess)
{
    m_dwProcessId = dwProcessId;
    m_hProcess = hProcess;
    if (m_sw)
        m_sw->m_hProcess = hProcess;
    return true;
}

PCONTEXT StackWalker::GetCurrentExceptionContext()
{
    return get_current_exception_context();
}

BOOL StackWalker::LoadModules()
{
    if (this->m_sw == NULL)
    {
        SetLastError(ERROR_DLL_INIT_FAILED);
        return FALSE;
    }
    if (m_modulesLoaded != FALSE)
        return TRUE;

    // Build the sym-path:
    char* szSymPath = NULL;
    if ((this->m_options & SymBuildPath) != 0)
    {
        const size_t nSymPathLen = 4096;
        szSymPath = (char*)malloc(nSymPathLen);
        if (szSymPath == NULL)
        {
            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
            return FALSE;
        }
        szSymPath[0] = 0;
        // Now first add the (optional) provided sympath:
        if (this->m_szSymPath != NULL)
        {
            strcat_s(szSymPath, nSymPathLen, this->m_szSymPath);
            strcat_s(szSymPath, nSymPathLen, ";");
        }

        strcat_s(szSymPath, nSymPathLen, ".;");

        const size_t nTempLen = 1024;
        char         szTemp[nTempLen];
        // Now add the current directory:
        if (GetCurrentDirectoryA(nTempLen, szTemp) > 0)
        {
            szTemp[nTempLen - 1] = 0;
            strcat_s(szSymPath, nSymPathLen, szTemp);
            strcat_s(szSymPath, nSymPathLen, ";");
        }

        // Now add the path for the main-module:
        if (GetModuleFileNameA(NULL, szTemp, nTempLen) > 0)
        {
            szTemp[nTempLen - 1] = 0;
            for (char* p = (szTemp + strlen(szTemp) - 1); p >= szTemp; --p)
            {
                // locate the rightmost path separator
                if ((*p == '\\') || (*p == '/') || (*p == ':'))
                {
                    *p = 0;
                    break;
                }
            } // for (search for path separator...)
            if (strlen(szTemp) > 0)
            {
                strcat_s(szSymPath, nSymPathLen, szTemp);
                strcat_s(szSymPath, nSymPathLen, ";");
            }
        }
        if (GetEnvironmentVariableA("_NT_SYMBOL_PATH", szTemp, nTempLen) > 0)
        {
            szTemp[nTempLen - 1] = 0;
            strcat_s(szSymPath, nSymPathLen, szTemp);
            strcat_s(szSymPath, nSymPathLen, ";");
        }
        if (GetEnvironmentVariableA("_NT_ALTERNATE_SYMBOL_PATH", szTemp, nTempLen) > 0)
        {
            szTemp[nTempLen - 1] = 0;
            strcat_s(szSymPath, nSymPathLen, szTemp);
            strcat_s(szSymPath, nSymPathLen, ";");
        }
        if (GetEnvironmentVariableA("SYSTEMROOT", szTemp, nTempLen) > 0)
        {
            szTemp[nTempLen - 1] = 0;
            strcat_s(szSymPath, nSymPathLen, szTemp);
            strcat_s(szSymPath, nSymPathLen, ";");
            // also add the "system32"-directory:
            strcat_s(szTemp, nTempLen, "\\system32");
            strcat_s(szSymPath, nSymPathLen, szTemp);
            strcat_s(szSymPath, nSymPathLen, ";");
        }

        if ((this->m_options & SymUseSymSrv) != 0)
        {
            if (GetEnvironmentVariableA("SYSTEMDRIVE", szTemp, nTempLen) > 0)
            {
                szTemp[nTempLen - 1] = 0;
                strcat_s(szSymPath, nSymPathLen, "SRV*");
                strcat_s(szSymPath, nSymPathLen, szTemp);
                strcat_s(szSymPath, nSymPathLen, "\\websymbols");
                strcat_s(szSymPath, nSymPathLen, "*https://msdl.microsoft.com/download/symbols;");
            }
            else
                strcat_s(szSymPath, nSymPathLen,
                    "SRV*c:\\websymbols*https://msdl.microsoft.com/download/symbols;");
        }
    } // if SymBuildPath

    // First Init the whole stuff...
    BOOL bRet = this->m_sw->Init(szSymPath);
    if (szSymPath != NULL)
        free(szSymPath);
    szSymPath = NULL;
    if (bRet == FALSE)
    {
        this->OnDbgHelpErr("Error while initializing dbghelp.dll", 0, 0);
        SetLastError(ERROR_DLL_INIT_FAILED);
        return FALSE;
    }

    bRet = this->m_sw->LoadModules(this->m_hProcess, this->m_dwProcessId);
    if (bRet != FALSE)
        m_modulesLoaded = TRUE;
    return bRet;
}

// The following is used to pass the "userData"-Pointer to the user-provided readMemoryFunction
// This has to be done due to a problem with the "hProcess"-parameter in x64...
// Because this class is in no case multi-threading-enabled (because of the limitations
// of dbghelp.dll) it is "safe" to use a static-variable
static StackWalker::PReadProcessMemoryRoutine s_readMemoryFunction = NULL;
static LPVOID                                 s_readMemoryFunction_UserData = NULL;

BOOL StackWalker::ShowCallstack(HANDLE                    hThread,
    const CONTEXT* context,
    PReadProcessMemoryRoutine readMemoryFunction,
    LPVOID                    pUserData)
{
    CONTEXT                                   c;
    CallstackEntry                            csEntry;
    IMAGEHLP_SYMBOL64* pSym = NULL;
    StackWalkerInternal::IMAGEHLP_MODULE64_V3 Module;
    IMAGEHLP_LINE64                           Line;
    int                                       frameNum;
    bool                                      bLastEntryCalled = true;
    int                                       curRecursionCount = 0;

    if (m_modulesLoaded == FALSE)
        this->LoadModules(); // ignore the result...

    if (this->m_sw->m_hDbhHelp == NULL)
    {
        SetLastError(ERROR_DLL_INIT_FAILED);
        return FALSE;
    }

    s_readMemoryFunction = readMemoryFunction;
    s_readMemoryFunction_UserData = pUserData;

    if (context == NULL)
    {
        // If no context is provided, capture the context
        // See: https://stackwalker.codeplex.com/discussions/446958
#if _WIN32_WINNT <= 0x0501
    // If we need to support XP, we need to use the "old way", because "GetThreadId" is not available!
        if (hThread == GetCurrentThread())
#else
        if (GetThreadId(hThread) == GetCurrentThreadId())
#endif
        {
            if (m_sw->m_ctx.ContextFlags != 0)
                c = m_sw->m_ctx;   // context taken at Init
            else
                GET_CURRENT_CONTEXT_STACKWALKER_CODEPLEX(c, USED_CONTEXT_FLAGS);
        }
        else
        {
            SuspendThread(hThread);
            memset(&c, 0, sizeof(CONTEXT));
            c.ContextFlags = USED_CONTEXT_FLAGS;

            // TODO: Detect if you want to get a thread context of a different process, which is running a different processor architecture...
            // This does only work if we are x64 and the target process is x64 or x86;
            // It cannot work, if this process is x64 and the target process is x64... this is not supported...
            // See also: http://www.howzatt.demon.co.uk/articles/DebuggingInWin64.html
            if (GetThreadContext(hThread, &c) == FALSE)
            {
                ResumeThread(hThread);
                return FALSE;
            }
        }
    }
    else
        c = *context;

    // init STACKFRAME for first call
    STACKFRAME64 s; // in/out stackframe
    memset(&s, 0, sizeof(s));
    DWORD imageType;
#ifdef _M_IX86
    // normally, call ImageNtHeader() and use machine info from PE header
    imageType = IMAGE_FILE_MACHINE_I386;
    s.AddrPC.Offset = c.Eip;
    s.AddrPC.Mode = AddrModeFlat;
    s.AddrFrame.Offset = c.Ebp;
    s.AddrFrame.Mode = AddrModeFlat;
    s.AddrStack.Offset = c.Esp;
    s.AddrStack.Mode = AddrModeFlat;
#elif _M_X64
    imageType = IMAGE_FILE_MACHINE_AMD64;
    s.AddrPC.Offset = c.Rip;
    s.AddrPC.Mode = AddrModeFlat;
    s.AddrFrame.Offset = c.Rsp;
    s.AddrFrame.Mode = AddrModeFlat;
    s.AddrStack.Offset = c.Rsp;
    s.AddrStack.Mode = AddrModeFlat;
#elif _M_IA64
    imageType = IMAGE_FILE_MACHINE_IA64;
    s.AddrPC.Offset = c.StIIP;
    s.AddrPC.Mode = AddrModeFlat;
    s.AddrFrame.Offset = c.IntSp;
    s.AddrFrame.Mode = AddrModeFlat;
    s.AddrBStore.Offset = c.RsBSP;
    s.AddrBStore.Mode = AddrModeFlat;
    s.AddrStack.Offset = c.IntSp;
    s.AddrStack.Mode = AddrModeFlat;
#else
#error "Platform not supported!"
#endif

    pSym = (IMAGEHLP_SYMBOL64*)malloc(sizeof(IMAGEHLP_SYMBOL64) + STACKWALK_MAX_NAMELEN);
    if (!pSym)
        goto cleanup; // not enough memory...
    memset(pSym, 0, sizeof(IMAGEHLP_SYMBOL64) + STACKWALK_MAX_NAMELEN);
    pSym->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
    pSym->MaxNameLength = STACKWALK_MAX_NAMELEN;

    memset(&Line, 0, sizeof(Line));
    Line.SizeOfStruct = sizeof(Line);

    memset(&Module, 0, sizeof(Module));
    Module.SizeOfStruct = sizeof(Module);

    for (frameNum = 0;; ++frameNum)
    {
        // get next stack frame (StackWalk64(), SymFunctionTableAccess64(), SymGetModuleBase64())
        // if this returns ERROR_INVALID_ADDRESS (487) or ERROR_NOACCESS (998), you can
        // assume that either you are done, or that the stack is so hosed that the next
        // deeper frame could not be found.
        // CONTEXT need not to be supplied if imageTyp is IMAGE_FILE_MACHINE_I386!
        if (!this->m_sw->pSW(imageType, this->m_hProcess, hThread, &s, &c, myReadProcMem,
            this->m_sw->pSFTA, this->m_sw->pSGMB, NULL))
        {
            // INFO: "StackWalk64" does not set "GetLastError"...
            this->OnDbgHelpErr("StackWalk64", 0, s.AddrPC.Offset);
            break;
        }

        csEntry.offset = s.AddrPC.Offset;
        csEntry.name[0] = 0;
        csEntry.undName[0] = 0;
        csEntry.undFullName[0] = 0;
        csEntry.offsetFromSmybol = 0;
        csEntry.offsetFromLine = 0;
        csEntry.lineFileName[0] = 0;
        csEntry.lineNumber = 0;
        csEntry.loadedImageName[0] = 0;
        csEntry.moduleName[0] = 0;
        if (s.AddrPC.Offset == s.AddrReturn.Offset)
        {
            if ((this->m_MaxRecursionCount > 0) && (curRecursionCount > m_MaxRecursionCount))
            {
                this->OnDbgHelpErr("StackWalk64-Endless-Callstack!", 0, s.AddrPC.Offset);
                break;
            }
            curRecursionCount++;
        }
        else
            curRecursionCount = 0;
        if (s.AddrPC.Offset != 0)
        {
            // we seem to have a valid PC
            // show procedure info (SymGetSymFromAddr64())
            if (this->m_sw->pSGSFA(this->m_hProcess, s.AddrPC.Offset, &(csEntry.offsetFromSmybol),
                pSym) != FALSE)
            {
                MyStrCpy(csEntry.name, STACKWALK_MAX_NAMELEN, pSym->Name);
                // UnDecorateSymbolName()
                this->m_sw->pUDSN(pSym->Name, csEntry.undName, STACKWALK_MAX_NAMELEN, UNDNAME_NAME_ONLY);
                this->m_sw->pUDSN(pSym->Name, csEntry.undFullName, STACKWALK_MAX_NAMELEN, UNDNAME_COMPLETE);
            }
            else
            {
                this->OnDbgHelpErr("SymGetSymFromAddr64", GetLastError(), s.AddrPC.Offset);
            }

            // show line number info, NT5.0-method (SymGetLineFromAddr64())
            if (this->m_sw->pSGLFA != NULL)
            { // yes, we have SymGetLineFromAddr64()
                if (this->m_sw->pSGLFA(this->m_hProcess, s.AddrPC.Offset, &(csEntry.offsetFromLine),
                    &Line) != FALSE)
                {
                    csEntry.lineNumber = Line.LineNumber;
                    MyStrCpy(csEntry.lineFileName, STACKWALK_MAX_NAMELEN, Line.FileName);
                }
                else
                {
                    this->OnDbgHelpErr("SymGetLineFromAddr64", GetLastError(), s.AddrPC.Offset);
                }
            } // yes, we have SymGetLineFromAddr64()

            // show module info (SymGetModuleInfo64())
            if (this->m_sw->GetModuleInfo(this->m_hProcess, s.AddrPC.Offset, &Module) != FALSE)
            { // got module info OK
                switch (Module.SymType)
                {
                case SymNone:
                    csEntry.symTypeString = "-nosymbols-";
                    break;
                case SymCoff:
                    csEntry.symTypeString = "COFF";
                    break;
                case SymCv:
                    csEntry.symTypeString = "CV";
                    break;
                case SymPdb:
                    csEntry.symTypeString = "PDB";
                    break;
                case SymExport:
                    csEntry.symTypeString = "-exported-";
                    break;
                case SymDeferred:
                    csEntry.symTypeString = "-deferred-";
                    break;
                case SymSym:
                    csEntry.symTypeString = "SYM";
                    break;
#if API_VERSION_NUMBER >= 9
                case SymDia:
                    csEntry.symTypeString = "DIA";
                    break;
#endif
                case 8: //SymVirtual:
                    csEntry.symTypeString = "Virtual";
                    break;
                default:
                    //_snprintf( ty, sizeof(ty), "symtype=%ld", (long) Module.SymType );
                    csEntry.symTypeString = NULL;
                    break;
                }

                MyStrCpy(csEntry.moduleName, STACKWALK_MAX_NAMELEN, Module.ModuleName);
                csEntry.baseOfImage = Module.BaseOfImage;
                MyStrCpy(csEntry.loadedImageName, STACKWALK_MAX_NAMELEN, Module.LoadedImageName);
            } // got module info OK
            else
            {
                this->OnDbgHelpErr("SymGetModuleInfo64", GetLastError(), s.AddrPC.Offset);
            }
        } // we seem to have a valid PC

        CallstackEntryType et = nextEntry;
        if (frameNum == 0)
            et = firstEntry;
        bLastEntryCalled = false;
        this->OnCallstackEntry(et, csEntry);

        if (s.AddrReturn.Offset == 0)
        {
            bLastEntryCalled = true;
            this->OnCallstackEntry(lastEntry, csEntry);
            SetLastError(ERROR_SUCCESS);
            break;
        }
    } // for ( frameNum )

cleanup:
    if (pSym)
        free(pSym);

    if (bLastEntryCalled == false)
        this->OnCallstackEntry(lastEntry, csEntry);

    if (context == NULL)
        ResumeThread(hThread);

    return TRUE;
}

BOOL StackWalker::ShowObject(LPVOID pObject)
{
    // Load modules if not done yet
    if (m_modulesLoaded == FALSE)
        this->LoadModules(); // ignore the result...

      // Verify that the DebugHelp.dll was actually found
    if (this->m_sw->m_hDbhHelp == NULL)
    {
        SetLastError(ERROR_DLL_INIT_FAILED);
        return FALSE;
    }

    // SymGetSymFromAddr64() is required
    if (this->m_sw->pSGSFA == NULL)
        return FALSE;

    // Show object info (SymGetSymFromAddr64())
    DWORD64            dwAddress = DWORD64(pObject);
    DWORD64            dwDisplacement = 0;
    const SIZE_T       symSize = sizeof(IMAGEHLP_SYMBOL64) + STACKWALK_MAX_NAMELEN;
    IMAGEHLP_SYMBOL64* pSym = (IMAGEHLP_SYMBOL64*)malloc(symSize);
    if (!pSym)
        return FALSE;
    memset(pSym, 0, symSize);
    pSym->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
    pSym->MaxNameLength = STACKWALK_MAX_NAMELEN;
    if (this->m_sw->pSGSFA(this->m_hProcess, dwAddress, &dwDisplacement, pSym) == FALSE)
    {
        this->OnDbgHelpErr("SymGetSymFromAddr64", GetLastError(), dwAddress);
        return FALSE;
    }
    // Object name output
    this->OnOutput(pSym->Name);

    free(pSym);
    return TRUE;
};

BOOL __stdcall StackWalker::myReadProcMem(HANDLE  hProcess,
    DWORD64 qwBaseAddress,
    PVOID   lpBuffer,
    DWORD   nSize,
    LPDWORD lpNumberOfBytesRead)
{
    if (s_readMemoryFunction == NULL)
    {
        SIZE_T st;
        BOOL   bRet = ReadProcessMemory(hProcess, (LPVOID)qwBaseAddress, lpBuffer, nSize, &st);
        *lpNumberOfBytesRead = (DWORD)st;
        //printf("ReadMemory: hProcess: %p, baseAddr: %p, buffer: %p, size: %d, read: %d, result: %d\n", hProcess, (LPVOID) qwBaseAddress, lpBuffer, nSize, (DWORD) st, (DWORD) bRet);
        return bRet;
    }
    else
    {
        return s_readMemoryFunction(hProcess, qwBaseAddress, lpBuffer, nSize, lpNumberOfBytesRead,
            s_readMemoryFunction_UserData);
    }
}

void StackWalker::OnLoadModule(LPCSTR    img,
    LPCSTR    mod,
    DWORD64   baseAddr,
    DWORD     size,
    DWORD     result,
    LPCSTR    symType,
    LPCSTR    pdbName,
    ULONGLONG fileVersion)
{
    CHAR   buffer[STACKWALK_MAX_NAMELEN];
    size_t maxLen = STACKWALK_MAX_NAMELEN;
#if _MSC_VER >= 1400
    maxLen = _TRUNCATE;
#endif
    if (fileVersion == 0)
        _snprintf_s(buffer, maxLen, "%s:%s (%p), size: %d (result: %d), SymType: '%s', PDB: '%s'\n",
            img, mod, (LPVOID)baseAddr, size, result, symType, pdbName);
    else
    {
        DWORD v4 = (DWORD)(fileVersion & 0xFFFF);
        DWORD v3 = (DWORD)((fileVersion >> 16) & 0xFFFF);
        DWORD v2 = (DWORD)((fileVersion >> 32) & 0xFFFF);
        DWORD v1 = (DWORD)((fileVersion >> 48) & 0xFFFF);
        _snprintf_s(
            buffer, maxLen,
            "%s:%s (%p), size: %d (result: %d), SymType: '%s', PDB: '%s', fileVersion: %d.%d.%d.%d\n",
            img, mod, (LPVOID)baseAddr, size, result, symType, pdbName, v1, v2, v3, v4);
    }
    buffer[STACKWALK_MAX_NAMELEN - 1] = 0; // be sure it is NULL terminated
    OnOutput(buffer);
}

void StackWalker::OnCallstackEntry(CallstackEntryType eType, CallstackEntry& entry)
{
    CHAR   buffer[STACKWALK_MAX_NAMELEN];
    size_t maxLen = STACKWALK_MAX_NAMELEN;
#if _MSC_VER >= 1400
    maxLen = _TRUNCATE;
#endif
    if ((eType != lastEntry) && (entry.offset != 0))
    {
        if (entry.name[0] == 0)
            MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, "(function-name not available)");
        if (entry.undName[0] != 0)
            MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, entry.undName);
        if (entry.undFullName[0] != 0)
            MyStrCpy(entry.name, STACKWALK_MAX_NAMELEN, entry.undFullName);
        if (entry.lineFileName[0] == 0)
        {
            MyStrCpy(entry.lineFileName, STACKWALK_MAX_NAMELEN, "(filename not available)");
            if (entry.moduleName[0] == 0)
                MyStrCpy(entry.moduleName, STACKWALK_MAX_NAMELEN, "(module-name not available)");
            _snprintf_s(buffer, maxLen, "%p (%s): %s: %s\n", (LPVOID)entry.offset, entry.moduleName,
                entry.lineFileName, entry.name);
        }
        else
            _snprintf_s(buffer, maxLen, "%s (%d): %s\n", entry.lineFileName, entry.lineNumber,
                entry.name);
        buffer[STACKWALK_MAX_NAMELEN - 1] = 0;
        OnOutput(buffer);
    }
}

void StackWalker::OnDbgHelpErr(LPCSTR szFuncName, DWORD gle, DWORD64 addr)
{
    CHAR   buffer[STACKWALK_MAX_NAMELEN];
    size_t maxLen = STACKWALK_MAX_NAMELEN;
#if _MSC_VER >= 1400
    maxLen = _TRUNCATE;
#endif
    _snprintf_s(buffer, maxLen, "ERROR: %s, GetLastError: %d (Address: %p)\n", szFuncName, gle,
        (LPVOID)addr);
    buffer[STACKWALK_MAX_NAMELEN - 1] = 0;
    OnOutput(buffer);
}

void StackWalker::OnSymInit(LPCSTR szSearchPath, DWORD symOptions, LPCSTR szUserName)
{
    CHAR   buffer[STACKWALK_MAX_NAMELEN];
    size_t maxLen = STACKWALK_MAX_NAMELEN;
#if _MSC_VER >= 1400
    maxLen = _TRUNCATE;
#endif
    _snprintf_s(buffer, maxLen, "SymInit: Symbol-SearchPath: '%s', symOptions: %d, UserName: '%s'\n",
        szSearchPath, symOptions, szUserName);
    buffer[STACKWALK_MAX_NAMELEN - 1] = 0;
    OnOutput(buffer);
    // Also display the OS-version
#if _MSC_VER <= 1200
    OSVERSIONINFOA ver;
    ZeroMemory(&ver, sizeof(OSVERSIONINFOA));
    ver.dwOSVersionInfoSize = sizeof(ver);
    if (GetVersionExA(&ver) != FALSE)
    {
        _snprintf_s(buffer, maxLen, "OS-Version: %d.%d.%d (%s)\n", ver.dwMajorVersion,
            ver.dwMinorVersion, ver.dwBuildNumber, ver.szCSDVersion);
        buffer[STACKWALK_MAX_NAMELEN - 1] = 0;
        OnOutput(buffer);
    }
#else
    OSVERSIONINFOEXA ver;
    ZeroMemory(&ver, sizeof(OSVERSIONINFOEXA));
    ver.dwOSVersionInfoSize = sizeof(ver);
#if _MSC_VER >= 1900
#pragma warning(push)
#pragma warning(disable : 4996)
#endif
    if (GetVersionExA((OSVERSIONINFOA*)&ver) != FALSE)
    {
        _snprintf_s(buffer, maxLen, "OS-Version: %d.%d.%d (%s) 0x%x-0x%x\n", ver.dwMajorVersion,
            ver.dwMinorVersion, ver.dwBuildNumber, ver.szCSDVersion, ver.wSuiteMask,
            ver.wProductType);
        buffer[STACKWALK_MAX_NAMELEN - 1] = 0;
        OnOutput(buffer);
    }
#if _MSC_VER >= 1900
#pragma warning(pop)
#endif
#endif
}

void StackWalker::OnOutput(LPCSTR buffer)
{
    OutputDebugStringA(buffer);
}

#endif